1. Chapter 2 The Chemistry of Life

2. Atoms Atoms are the smallest part of matter Made up of
Protons – Positive charge, found in
nucleus
Neutrons – no charge, found in nucleus
Electrons – Negative charge, found
outside the nucleus

3. Determining atomic number, atomic weight and neutrons
Atomic number is the number of protons in the atom
Atomic weight is the sum of the mass of the protons, neutrons, and electrons in an atom
Number of neutrons can be determined by subtracting the atomic number from the atomic mass (rounded).

4. Electron shell model

5. Electron placement
Bohr atom vs. modern interpretation

6. Compounds and molecules
Compound - two or more elements chemically combined; Hydrogen and Oxygen combine to form water
Molecule - smallest unit of a compound that retains the properties of the compound; H2O

7. B. Chemical Bonding

8. 1. Ionic bonding 2. Covalent bonding 3. Hydrogen bonding
Giving away or taking of electrons
Ionic bond formation in sodium chloride
2. Covalent bonding
Sharing of electrons
Covalent bond formation in methane
3. Hydrogen bonding
formed by the attraction of oppositely charged poles of molecules. Example in water; a weak bond

9. Properties of Water
Because of the hydrogen bonds between water molecules, water is “sticky”
Cohesion – Water sticks to itself (penny lab)
Adhesion – Water sticks to other surfaces (capillary action, wet)

11. 4. Chemical reactions 5. Acids and bases
Chemical reaction - process in which atoms or molecules interact and form new bonds.
Can be characterized by release or taking in of heat, color change, gas, etc.
5. Acids and bases
Acids have a pH below 7, sour tasting and turn litmus paper red
Bases have a pH above 7, taste bitter, and turn litmus paper blue

12. pH Scale

13. C. Major Organic Compounds of Living Things

15. 1. Carbohydrates 2. Lipids Composed of carbon, hydrogen, and oxygen
Monosaccharides, disaccharides, and polysaccharides
Important as a food source
2. Lipids
Fats; found in cell membranes, steroids
Used for energy storage
Generally do not dissolve in water

17. 3. Proteins 4. Nucleic acids Composed of long chains of amino acids
Include enzymes and structural materials
Primary, secondary, and tertiary protein structure; can be denatured
4. Nucleic acids
Composed of a sugar, phosphate and nitrogenous bases
Bases: Adenine, Guanine, Cytosine, Thymine, Uracil
Hereditary material

19. Enzymes Special proteins that speed up and control chemical reactions
Usually named after the substances they act upon
Often end in –ase
Catalase, Lactase, Ribonuclease, etc.
Animation

20. Enzymes lower acivation energy

22. Enzymes Lower the amount of energy needed for a reaction to proceed
Are not used up during the reaction, and can be used over and over again
Control your body’s metabolism (all chemical reactions in your body)
Are affected by heat, temperature, and pH, they can be denatured (destroyed)